Convolute section

ABSTRACT

A convolute section for use in a pressure suit has adjustable root cords slidably attached to the restraint cloth by stitching, preferably by zigzag stitching.

United States Patent Inventors Appl. No

Filed Patented Assignee John Korabowski Springfield, Mass.;

Edwin G. Vail, Simsbury, Conn.

Dec. 20, 1968 Apr. 13, 197 1 United Aircraft Corporation East Hartford, Conn.

CONVOLUTE SECTION 1 Claim, 3 Drawing Figs.

U.S.Cl

lnt.C1 .1

Field of Search ,.2/2,211,2.1 (A), 184,237; 138/121, 118, 119, 1213;285/226, 235', 178/144; 112/413, 265

[56] References Cited UNITED STATES PATENTS 218,220 8/1879 Bigelow 2/184X 963,744 7/1910 Carter 112/413 2,967,305 1/1961 White et a1. 1 2/2. 1 (A) 2,392,992 1/1946 Martin 2/2.1 2,410,632 11/1946 Colley et a1 2/2. 1 (A) FOREIGN PATENTS 564,636 11/1932 Germany 112/413 Primary Examiner-Jordan Franklin, Jr. Assistant Examiner-George H. Krizmanich Attorney-James A. Kane ABSTRACT: A convolute section for use in a pressure suit has adjustable root cords slidably attached to the restraint cloth by stitching, preferably by zigzag stitching.

l t I. I t I. I I

Patented April 13, 1971 3,574,863

flfflfK/Kf CONVOLUTE SECTION BACKGROUN D OF THE INVENTION This invention relates to convolute sections and the method for making convolute sections for use in pressure suits.

Pressurized suits designed for space or high altitude aviation use must of necessity have flexible sections which permit freedom of movement of the wearer's body and limbs. These sections should be relatively easy to move, should allow a sufficient degree of freedom, and should conform to the human anatomy so as to prevent pressure points from developing when the suit is pressurized.

The principal type of suit construction, which prior art suits have utilized to satisfy the foregoing objectives, has been a convolute section. Typically in these prior art convolute sections, a root cord construction is utilized. The primary deficiencies with the root cord construction in such prior art convolute sections are twofold, in that, normally the root cords are attached to the restraint cloth of the section by a tunnel tape-type construction, this being a costly and timeconsuming process to apply. Additionally, the root cord constructions in prior'art convolute sections have not been satisfactory from a performance standpoint inasmuch as the root cord dimension, and hence volume, has been relatively large, thereby causing the material to bunch up in the section when bent and hence reduce performance, particularly in the pressurized state.

The present invention, by utilizing stitching to restrain the root cord adjacent the convolute cloth avoids the foregoing problems in that it provides a relatively small volume in the root area, reduces the overall weight of the suit, and additionally provides. an improved bendable section and joint performance over the prior art construction.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide a unique convolute section and the method of manufacturing therefor, the convolute section utilizing stitching to restrain a root adjacent to the restraint cloth of the convolute section, the stitching being applied around the root cord but through the restraint cloth so that the root cord is slidable beneath the stitching.

In manufacturing a convolute section in accordance with the present invention, a flat piece of restraint fabric or cloth has a plurality of root cords, spaced from one another thereon and positioned in the intended area of the root of each convolute. Once the cords have been positioned on the fabric, each cord is restrained with respect to the convolute fabric by means of a zigzag stitch, the stitching passing over the cords but into the fabric so as to permit each cord to be freely slidable beneath the stitching. It is pointed out that the zigzag type stitch is the preferred embodiment but that other type stitches may be suitable provided the root cords are slidable thereunder. Once the root cords have been restrained adjacent the restraint cloth or fabric, in this manner, they are free to be adjusted to any length and thereby provide a predetermined or desired shape and volume of the convolute section. Obviously, the shape and volume and therefore the circumferential-tolength ratio of the joint depends upon which suit joint is being manufactured.

The obvious advantage of attaching the adjustable root cords to the convolute restraint cloth in this manner is the elimination of any bulk in the root area, thereby providing a desired volume and shape and avoiding bunching up of restraint cloth in the root area of the convolute section when in a joint which is flexed in a pressurized condition. By reducing the bulk when a convoluted joint is flexed, it has been found that the force required to flex the joint in an unpressurized state and in a pressurized state is substantially the same; or more particularly, no greater force is necessary to flex the joint in the pressurized condition than in the unpressurized condition. The method of manufacturing described herein further leads to the advantage of providing a joint which is easily and rapidly manufactured, hence reducing the cost of manufacturing the convolute section, in fact, it has been found thata convolute section may be manufactured by the technique described herein approximately one-third faster than by manufacturing methods typical of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an illustrative showing of a flat pattern for a convolute section with the root cords positioned thereon.

FIG. 2 is an illustrative showing of a partially formed convolute section.

FIG. 3 is a showing of a typical prior art convolute root cord attachment arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. I in utilizing the method of the present invention, a plurality of root cords 4 are positioned on a substantially flat cloth pattern 2. Pattern 2 actually comprises the restraint cloth of the appropriate joint or pressure suit portion which is utilizing the technique herein described. It is pointed out that the present invention is applicable equally to any convolute section in a pressure suit, e.g., the shoulder, elbow, wrist, fingers, torso, waist, hip, thigh, knee and ankle; and any of these foregoing sections may be manufactured employing the method described therein.

Cords 4 are positioned on pattern 2 in a spaced manner, the spacing being axially with respect to the centerline 6 of pattern 2. In the present embodiment, the spacing of cords 4 is such that they are positioned substantially in the intended root area 8 between each convolute 10 (See FIG. 2). After the cords 4 are positioned on pattern 2, each of the cords 4 are slidably attached thereto by means of zigzag stitching 12, which pierces the fabricor cloth '2, but passes over the cords 4. It is reiterated that the zigzag-type stitch (as illustrated in FIG. I) is a preferred type stitch, but that any type stitch which slidably retains the root cords 4 to the restraint cloth 2 would be suitable.

The retaining of root cords 4 to the cloth of pattern 2 is unique in that each cord 4 is slidably retained under zigzag stitching 12. Therefore, after the zigzag stitching has been applied. the length of each cord 4 can be adjusted to provide a desired shape and volume, the foregoing depending on which type of convolute section is being manufactured.

The convolute section illustrated in FIG. 2 is typical of an elbow joint 20 for use in a pressure suit. Elbow joint 20 has been manufactured by joining the edges of the fabric pattern 2 which are parallel to the centerline 6 (FIG. 1) so as to form a generally cylindrical section, and comprise convolutes I0, formed by adjusting the length of root cords 4, positioned in the root area 8 between each convolute 10, to a diameter less than the diameter of the generally cylindrical section of the fabric 2, as a result of zigzag stitching 12 which permits root cords 4 to be adjustable to any desired circumference, the ends of the root cords then being mutually secured, such as by tying. A restraint member 14 which provides the desired length of the joint or section is not a part of the present invention. The convolute section shown in FIG. 2 illustrates how the present invention provides a convolute section or joint wherein the volume, and hence bulk in the root area, is virtually eliminated by the unique application of the zigzag stitching. For comparison purposes, FIG. 3 illustrates a typical prior art arrangement for the restraining of root cords 30 in tunnels formed by means of restraint tapes 32 being attached cloth section, said cords being disposed along the outside of said generally cylindrical restraint cloth section substantially perpendicular to the axis thereof and spaced I apart from one another, thereby forming convolutes in said generally cylindrical restraint cloth section; and

a plurality of stitches passing over each root cord along 

1. In a pressure suit, a convoluted structure comprising: a generally cylindrical restraint cloth section; a plurality of inextensible root cords, each having its ends adjustably secured so as to comprise closed loops capable of assuming a generally circular shape of a diameter less than the diameter of said generally cylindrical restraint cloth section, said cords being disposed along the outside of said generally cylindrical restraint cloth section substantially perpendicular to the axis thereof and spaced apart from one another, thereby forming convolutes in said generally cylindrical restraint cloth section; and a plurality of stitches passing over each root cord along substantially the entire length thereof and piercing said generally cylindrical cloth section adjacent each side of the root cord so that said root cords are slidably restrained between said stitches and adjacent portions of said cloth. 